The Grayling is now largely confined to coastal habitats in Britain (having disappeared from many of its inland sites due to changes in land-use), where it occurs on well-drained sites in short open grassland where the vegetation is sparse and where there are plenty of patches of bare ground. The larvae feed on various grasses, but especially fine-leaved species. (For further details on this species see http://www.butterfly-conservation.org/).

Status details : Status since 1976 is Rapid decline with a decrease of -72.4%Status over the last 20 years is Rapid decline with a decrease of -50.6%Status over the last 10 years is Rapid decline with a decrease of -63.2%

Log collated index plot

This chart shows the index of abundance (LCI = Log Collated Index) over time. It shows fluctuations in
populations from year to year, and is scaled so that the average index over the whole series is equal to 2
(horizontal line). For greater detail about how this index is derived, click on the green question mark above.

Trend description :The trend for this species shows a highly significant decline over the monitoring period. There was a particularly sharp drop in 1984-6 from which the species made a partial recovery in the years 1989-90 following one of its worst indices of the series in 1988. Since the early 90s there was another pattern of decline, but the short term trend for Grayling is weakly positive with the population on monitored sites becoming stable despite extremely low indices such as that produced in 2007. Climate change and warmer summer temperatures would be expected to improve conditions for this butterfly in the UK. However, continued habitat destruction and lack of appropriate management to maintain suitable habitat seem to be the main factors in this decline and are likely to be preventing any positive climate effects.

Phenology plot

Phenology plot

This chart shows the average number of butterflies seen on transects between Arpil and October across all sites (fitted values from a Generalised Additive Model). The blue line gives average counts over the full BMS series (1976 to date) and the red line gives the average for the last year.

This map shows symbols for the mean abundance at transect sites, with the colour of the symbol reflecting the level of abundance. Means are over all years. Grey background squares are the occupied cells as shown by the Butterflies for the New Millenium over the previous ten year period.

Coverage

In total, Grayling has been recorded from 294 transects in the Butterfly Monitoring Scheme. Of these, annual indices of abundance have been calculated from 225 sites, with an average index of 39 individuals per site.

For 114 of these sites, Grayling has been recorded well enough to calculate annual indices of abundance in more years, allowing trends to be calculated.

In 2017, 6216 individuals were recorded from 92 sites, producing annual indices at 72 of these.

This map shows the trend in abundance at particular transect sites for which data has been received within the last five years. Trends (increasing, declining or stable) are assessed at sites where the species has more than five years of annual index data. Use the option boxes below to view plots for individual sites.